Entries in LMP1
(4)

Audi has made some significant changes to its R18 Le Mans racer. It has moved up into the 6 megajoule class from four, revised the aerodynamics, upgraded the engine and transmission, replaced the safety cell, and switched from a flywheel energy storage system to a lithium-ion battery. In many ways, the new car comes closer to the engineering ideas used by sister division Porsche on its Le Mans racer.

Audi used a flywheel energy recovery system from 2012 to 2015, but has dropped this tried-and-true electrokinetic storage system for an electrochemical system based around production-based lithium-ion battery cells. “The flywheel accumulator definitely proved viable for the lower energy classes,” explains Thomas Laudenbach, Head of Electrics, Electronics and Energy Systems at Audi Sport. “But due to the fact that we now have to process 50% more energy than before, a technology change suggested itself.”

Electrification is the word for this year’s 24 Hours of Le Mans. The rule makers at the ACO have insisted on a 30% efficiency improvement for the LMP1 competitors, while Nissan is back with an electrified hardtop DeltaWing derivative running under the Garage 56 designation. And while one of the Nissan’s main functions is to prepare the ground for the company’s return in 2015 with a full-on hybrid LMP1 racer, Porsche is going for the overall win after a long layoff. It is up against tough competition from stablemate (and multiple Le Mans winner) Audi, and a very strong entry from Toyota.

Honda Performance Development (HPD) has created a new powertrain for endurance racing. Based on the architecture of the 2.2-liter direct-injected turbocharged V6 it supplies for the IndyCar series, the HR22T has been designed in concert with a Magneti Matelli energy recovery system. This combination will give privateers the chance to compete under the World Endurance Championship’s (WEC) new LMP1 regulations.

The new rules package debuts next year, and eliminates the current displacement and air inlet limits. These have been replaced by a limit on maximum fuel flow into the engine, with different flow rates for those vehicles with or without energy recovery systems. This gives the non-factory teams the chance to compete with the best energy solution, and gives them the choice of no energy recovery or up to a full eight Megajoules. Wirth Research is developing a coupe version of HPD’s ARX chassis for the new V6 and energy recovery system.

With the LMP1 class not supported by the new United Sports Car Racing series, Honda will continue to support its ARX-03b chassis and production-based HR28TT V6. It is the only engine in the LMP2 class to include both a twin turbocharging and direct injection, and will continue to run in both the newly combined North American series and WEC. — CAS

The Lola-Drayson B12/69EV is a most unusual Le Mans prototype. It has a reputed 850 horsepower, but no piston engine. It is built around Lola’s current LMP1 chassis, but will not run in any races. Plus, the Lola-Drayson racer uses a new technology from BAE Systems that uses “structural batteries” to store electrical energy within the physical structure of a device.

Created to reduce the physical size and bulk of the electronics the modern soldier must carry, structural batteries merge battery chemistry into composite materials that can be molded into 3D shapes and form the structure of the device itself. Currently, the process makes use of nickel-based battery chemistry, but work is already underway on lithium-ion and lithium-polymer chemistries. It is not yet ready to replace the Lola-Drayson car’s battery pack with lithium-impregnated carbon composite bodywork, but the rear wing’s upper element and rear diffuser will utilize structural battery technology to power some of the onboard electrical systems. As the technology improves, this usage will increase.